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Experimental Investigation of a Fixed-geometry Two-dimensional Mixed-compression Supersonic Inlet with Sweep-forward High- light and Bleed Slot in an Inverted ＂X＂-type Layout

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Chinese Journal of Aeronautics 2007年第4期20卷 304-312页

作者： Wan Dawei guo rongwei College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate：（1） with increases of the free stream Mach number, the total pressure recovery decreases, while the mass flow ratio increases to the maximum at the design point and then decreases; （2） when the angle of attack, a, is less than 6°, the total pressure recovery of both side inlets tends to decrease, but, on the lee side inlet, its values are higher than those on the windward side inlet, and the mass flow ratio on lee side inlet increases first and then falls, while on the windward side it keeps declining slowly with the sum of mass flow on both sides remaining almost constant; （3） with the attack angle, a, rising from 6° to 9°, both total pressure recovery and mass flow ratio on the lee side inlet fall quickly, but on the windward side inlet can be observed decreases in the total pressure recovery and increases in the mass flow ratio; （4） by comparing the velocity and back pressure characterristics of the inlet with a bleed slot to those of the inlet without, it stands to reason that the existence of a bleed slot has not only widened the steady working range of inlet, but also made an enormous improvement in its performance at high Mach numbers. Besides, this paper also presents an example to show how this type of inlet is designed.

关键词： aerospace propulsion system supersonic inlet two-dimensional mixed-compression experimental investigation bleed slot "X"-type sweep-forward high-light

Numerical study of unsteady starting characteristics of a hypersonic inlet

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Chinese Journal of Aeronautics 2013年第3期26卷 563-571页

作者： Wang Weixing guo rongwei College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics

The impulse and self starting characteristics of a mixed-compression hypersonic inlet designed at Mach number of 6.5 are studied by applying the unsteady computational fluid dynamics （CFD） method. The full Navier–Stokes equations are solved with the assumption of viscous perfect gas model, and the shear-stress transport （SST） k–x two-equation Reynolds averaged Navier– Stokes （RANS） model is used for turbulence modeling. Results indicate that during impulse starting, the flow field is divided into three zones with different aerodynamic parameters by primary shock and upstream-facing shock. The separation bubble on the shoulder of ramp undergoes a generating, growing, swallowing and disappearing process in sequence. But a separation bubble at the entrance of inlet exists until the freestream velocity is accelerated to the starting Mach number during self starting. The mass flux distribution of flow field is non-uniform because of the interaction between shock and boundary layer, so that the mass flow rate at throat is unsteady during impulse starting. The duration of impulse starting process increases almost linearly with the decrease of freestream Mach number but rises abruptly when the freestream Mach number approaches the starting Mach number. The accelerating performance of booster almost has no influence on the self starting ability of hypersonic inlet.

关键词： Hypersonic flow Inlet Scramjet Start Unsteady

Unsteady flow characteristic analysis of turbine based combined cycle(TBCC)inlet mode transition10.1016/***.2015.07.006

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Propulsion and Power Research 2015年第3期4卷 141-149页

作者： Jun Liu Huacheng Yuan rongwei guo Nanjing University of Aeronautics and Astronautics Jiangsu Province Key Laboratory of Aerospace Power SystemNanjing 210016China Collaborative Innovation Center for Advanced Aero-Engine Beijing 100191China

A turbine based combined cycle(TBCC)propulsion system uses a turbine-based engine to accelerate the vehicle from takeoff to the mode transition flight condition,at which point,the propulsion system performs a“mode transition”from the turbine to ramjet *** inlet mode transition is accomplished when flow is diverted from one flowpath to the other,without experiencing unstart or *** smooth inlet mode transition is a complex unsteady process and it is one of the enabling technologies for combined cycle engine to become a functional *** order to unveil the unsteady process of inlet mode transition,the research of over/under TBCC inlet mode transition was conducted through a numerical *** shows that during the mode transition the terminal shock oscillates in the *** the process of inlet mode transition mass flow rate and Mach number of turbojet flowpath reduce with *** in ramjet flowpath the flow field is non-uniform at the beginning of inlet mode *** speed of mode transition and the operation states of the turbojet and ramjet engines will affect the motion of terminal *** result obtained in present paper can help us realize the unsteady flow characteristic during the mode transition and provide some suggestions for TBCC inlet mode transition based on the smooth transition of thrust.

关键词： Airbreathing hypersonic vehicle Turbine based combined cycle(TBCC) Inlet mode transition Unsteady numerical simulation Shock oscillation

Input/output-to-state stable property of switched stochastic nonlinear systems by an improved average dwell time method

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Input/output-to-state stable property of switched stochastic...

Stability Analysis of Switched Nonlinear Systems with an improved Mode-dependent Average Dwell Time Method

第26届中国控制与决策会议

作者： REN Ling guo rongwei ZHAO Ping LI Bin School of Control Science and Engineering Shandong University

ISBN: (纸本)9781479937066

This paper investigates the input/output-to-state stable in the mean（IOSSiM） property of switched stochastic nonlinear（SSN） systems. First, we present a new IOSSiM result for the SSN systems whose subsystems are IOSSiM by applying an improved ADT method. Second, by extending the improved ADT method to unforced nominal SSN systems in which parts of subsystems are stable, we establish a new stability analysis result. It should be pointed out that the obtained results have two advantages over the existing results, one is the ADT conditions are simplified, the other is the obtained lower bound of ADT（τ*a） is also smaller than those obtained by other methods. Finally, an illustrative example with numerical simulation is verified the correctness and the effectiveness of the proposed methods.

关键词： Switched stochastic nonlinear system Input/output-to-state stable Unstable subsystems Average dwell time

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Stability Analysis of Switched Nonlinear Systems with an imp...

第26届中国控制与决策会议

作者： REN Ling guo rongwei ZHAO Ping LI Bin School of Control Science and Engineering Shandong University

ISBN: (纸本)9781479937066

This paper investigates the stability for a class of switched nonlinear systems. Firstly, an improved average dwell time（ADT） method is introduced, based on which an improved mode-dependent dwell time（MDDT） method is established. Then, several new results to the stability analysis are obtained. In comparison with the existing results, the obtained results have some advantages over those obtained by others. Finally, an illustrative example with numerical simulation is studied to show the correctness and validity of our results.

关键词： Switched nonlinear system Stability Average dwell time Mode-dependent averaged dwell time

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蛇形进气道地面工作状态附面层抽吸试验研究

南京航空航天大学学报 2007年第1期39卷 30-36页

作者：靖建朋郭荣伟南京航空航天大学能源与动力学院

对一种蛇形进气道开展了地面工作状态下的抽吸试验研究,结果表明,在该状态下进气道出口截面的总压恢复系数较低、流场畸变较大。为此,本文采用附面层抽吸技术对其进行了地面抽吸状态下的流场控制试验研究。研究结果表明:(1)地面工作状态... 详细信息

对一种蛇形进气道开展了地面工作状态下的抽吸试验研究,结果表明,在该状态下进气道出口截面的总压恢复系数较低、流场畸变较大。为此,本文采用附面层抽吸技术对其进行了地面抽吸状态下的流场控制试验研究。研究结果表明:(1)地面工作状态下,随着出口马赫数的增加,蛇形进气道出口截面的总压恢复系数不断下降,而稳态周向畸变指数、紊流度和综合畸变指数均上升,稳态径向畸变指数变化不大。本研究的蛇形进气道在出口马赫数为0.45时,总压恢复系数为0.90,综合畸变指数为13.85%,总压恢复较低,畸变较大,超出了一般航空发动机的承受范围。(2)与原型方案的地面抽吸试验结果相比,采用附面层抽吸技术后,进气道出口截面的总压恢复系数得到了提高。在出口马赫数为0.45,相对抽吸量为0.043时总压恢复系数提高了2.6%。

关键词：蛇形进气道流场控制地面工作状态附面层抽吸试验相对抽吸量

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蛇形进气道的电磁散射特性

航空学报 2007年第6期28卷 1296-1301页

作者：石磊郭荣伟南京航空航天大学能源与动力学院江苏南京210016

对一种进口与机身保形设计的蛇形进气道在Ku波段选择入射频率15GHz情况下进行了电磁散射特性的实验和仿真研究,取得了蛇形进气道雷达散射截面(RCS)随方位角、迎角和终端的变化规律。研究结果表明:(1)该蛇形进气道在水平极化终端为风扇时... 详细信息

对一种进口与机身保形设计的蛇形进气道在Ku波段选择入射频率15GHz情况下进行了电磁散射特性的实验和仿真研究,取得了蛇形进气道雷达散射截面(RCS)随方位角、迎角和终端的变化规律。研究结果表明:(1)该蛇形进气道在水平极化终端为风扇时±60°RCS均值为-24.33dB.m2,垂直极化为-19.15dB.m2,是一种低RCS进气道;(2)运用时域有限差分法计算所得的RCS随方位角变化曲线与实验曲线趋势基本一致,±60°均值误差在4dB以内;(3)从进气道对称面电场(Ex)分布图可以看出入射波射入进气道并在内壁面产生多次反射,从而验证了蛇形进气道的设计思想并为在内通道关键反射点涂敷吸波材料实现蛇形进气道的高隐身提供了一个可行的研究平台。

关键词：航空航天推进系统蛇形进气道电磁散射隐身技术

Stabilization of a class of chaotic systems by the control design of triangular system

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Stabilization of a class of chaotic systems by the control d...

第37届中国控制会议

作者： Zuoxun Wang rongwei guo School of Electrical Engineering and Automation Qilu University of Technology School of Science Qilu University of Technology

This paper investigates the stabilization problem of a class of chaotic systems in arbitrary dimensions by the control design of triangular ***,a single input linear feedback control method for the triangular systems is introduced,based on which some new results about stabilization of such chaotic systems are then proposed in three *** is noted that all the obtained controllers are single input linear controllers and easier to be designed and implemented in ***,illustrative examples with numerical simulations are applied to verify the correctness and effectiveness of the obtained results.

关键词： chaotic system stabilization triangular system single input linear feedback control

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一种高超声速二元混压式进气道的研究

航空学报 2009年第12期30卷 2288-2294页

作者：谢旅荣郭荣伟南京航空航天大学能源与动力学院江苏南京210016

针对飞行马赫数为6.00的二元进气道模型开展了高焓脉冲风洞试验研究,分析了进气道在不设置反压和设置反压两种情况下的激波结构、内通道皮托压分布及隔离段出口的性能,并结合数值仿真分析了通道内的流场特性。研究结果表明:在无反压情况... 详细信息

针对飞行马赫数为6.00的二元进气道模型开展了高焓脉冲风洞试验研究,分析了进气道在不设置反压和设置反压两种情况下的激波结构、内通道皮托压分布及隔离段出口的性能,并结合数值仿真分析了通道内的流场特性。研究结果表明:在无反压情况下,进气道内通道激波反射明显,靠近下壁面的皮托压值均低于其他测点,在隔离段出口截面,靠近侧壁皮托压有所降低;在一定反压条件下,结尾激波系上传至隔离段内,结尾激波位置不对称;堵塞度为62%的反压条件下,结尾激波系位于喉道位置,隔离段出口截面下半部分已经是亚声速流动;在来流马赫数Ma=6.07,迎角α=4.5°无反压情况下,隔离段出口总压恢复系数为0.477,平均马赫数为2.72,增压比为44,流量系数为0.81,表明进气道性能良好。

关键词：航空航天推进系统吸气式高超声速飞行器二元进气道风洞试验数值模拟